unselectedIconTheme property Null safety
final
The size, opacity, and color of the icon in the currently unselected BottomNavigationBarItem.icons.
If BottomNavigationBar.unselectedIconTheme is non-null on the widget, the whole IconThemeData from the widget will be used over this unselectedIconTheme.
Implementation
final IconThemeData? unselectedIconTheme;